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.TH AIO_RETURN 3C "Feb 5, 2008"
.SH NAME
aio_return \- retrieve return status of an asynchronous I/O operation
.SH SYNOPSIS
.LP
.nf
#include <aio.h>

\fBssize_t\fR \fBaio_return\fR(\fBstruct aiocb *\fR\fIaiocbp\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBaio_return()\fR function returns the return status associated with the
\fBaiocb\fR structure referenced by the \fIaiocbp\fR argument. The return
status for an asynchronous I/O operation is the value that would be returned by
the corresponding \fBread\fR(2), \fBwrite\fR(2), or \fBfsync\fR(3C) function
call. If the error status for the operation is equal to \fBEINPROGRESS\fR, then
the return status for the operation is undefined. The \fBaio_return()\fR
function may be called exactly once to retrieve the return status of a given
asynchronous operation; thereafter, if the same \fBaiocb\fR structure is used
in a call to \fBaio_return()\fR or \fBaio_error\fR(3C), an error may be
returned. When the \fBaiocb\fR structure referred to by \fIaiocbp\fR is used to
submit another asynchronous operation, then \fBaio_return()\fR may be
successfully used to retrieve the return status of that operation.
.SH RETURN VALUES
.sp
.LP
If the asynchronous I/O operation has completed, then the return status, as
described for \fBread\fR(2), \fBwrite\fR(2), and \fBfsync\fR(3C), is returned.
If the asynchronous I/O operation has not yet completed, the results of
\fBaio_return()\fR are undefined.
.SH ERRORS
.sp
.LP
The \fBaio_return()\fR function will fail if:
.sp
.ne 2
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 10n
The \fIaiocbp\fR argument does not refer to an asynchronous operation whose
return status has not yet been retrieved.
.RE

.sp
.ne 2
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 10n
The \fBaio_return()\fR function is not supported by the system.
.RE

.SH USAGE
.sp
.LP
The \fBaio_return()\fR function has a transitional interface for 64-bit file
offsets.  See \fBlf64\fR(7).
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
_
MT-Level	Async-Signal-Safe
_
Standard	See \fBstandards\fR(7).
.TE

.SH SEE ALSO
.sp
.LP
.BR close (2),
.BR exec (2),
.BR exit (2),
.BR fork (2),
.BR lseek (2),
.BR read (2),
.BR write (2),
.BR aio_cancel (3C),
.BR aio_fsync (3C),
.BR aio_read (3C),
.BR fsync (3C),
.BR lio_listio (3C),
.BR aio.h (3HEAD),
.BR signal.h (3HEAD),
.BR attributes (7),
.BR lf64 (7),
.BR standards (7)
.SH NOTES
.sp
.LP
Solaris 2.6 was the first release to support the Asynchronous Input and Output
option. Prior to this release, this function always returned \fB\(mi1\fR and
set \fBerrno\fR to \fBENOSYS\fR.
